This last post from Mike of Hessle rouses my taxonomic hackles suspiciously. It is a very old joke: & I don't believe any Xmas cracker manufacturer would enclose it in a cracker intended to be pulled, as likely as not, by a small child. If I am right, it belongs on the 'joke thread' rather than here — except, as I say, that anyone reading that will have known it for the last umpteen years anyhow.